Extension-ladder



G. WQH, MOULTON.

EXTENSION LADDER.

Patented Mar. 24, 1896.

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CHARLES \V. IL MOULTON, OF CAMBRIDGE, MASSACHUSETTS.

EXTENSION-LADDER.

SPECIFICATION forming part of Letters Patent No. 556,831, dated March24, 1896.

Application filed November 6, 1895. serial No. 568,092. (No model.)

To all whom it may concern.-

Be it known that 1, CHARLES W. H. Moun- TON, of Cambridge, in the countyof Middlesex and State of Massachusetts, have invented a new and usefulImprovement in Extension- Ladders, which will, in connection with theaccompanying drawings, be hereinafter fully described and specificallydefined in the appended claims.

In said drawings, Figure 1 represents parts of an extension-ladder withmy invention thereto applied; and Fig. 2 is a sectional elevation, thesection being vertical through the rungs shown in Fig. 1 and the view asfrom the left in Fig. 1.

My invention relates to an improvement in extension-ladders which areprovided with pawls that secure the upper half at any desired positionupon the lower half; and it con sists in a stay that supports thepivot-bolt and at the same time arrests the movement of the pawl when itis being revolved on said pivot, so that it cannot move beyond avertical position when being turned up.

It also consists in so forming the lower locks of the ladder that saidpawls when turned downward will be arrested when they reach the lowestpoint, so that they cannot revolve through more than a half-circle whenthe ladder is provided with my improvements.

Referring again to said drawings, A A rep resent the standards of thelower section of the ladder, the same being secured in position by theusual rungs a. The lower part of the upper section is shown at B B,which parts are united by rungs and shown at 2'. The pawls that hold thetop sect-ion at the desired height are shown, as at D, but one beingdeemed necessary to be here shown. This pawl is pivoted upon bolt d, andit is formed with longer finger b, shorter finger c, and a counterweight6, so that said top section can be raised and lowered by the automaticaction of said pawls. As the striking of said pawls against. the rungs acauses them to be whirled upon their pivot, to the great inconvenienceof the user, I form the lower ladder-locks O, which are riveted to thetop section by rivet k, as shown, to extend inside pieces B, as shown inFig. 1, far enough to arrest the pawl when it is thrown back by end ofwhich said bolt (1 is inserted, while at the upper end said bar is bentat right angles and the short arm g is secured in part B, as shown. Thelength of barf is such that when pawl D is thrown up it is arrested byarm g, as shown by dotted lines in Fig. 2. By this construction of barf, arm g, and bolt cl, the pawl cannot swing beyond arm g, and bolt (1is secured firmly in place and cannot bend. Bar f and part 01 and 9could all be formed as an integral piece, or both (1 and 9 may beinserted; but I prefer the construction shown.

Bolt cl is formed with a shoulder against which washer & bears, so thatpawl D cannot be pinched between bar f and the sides B when the nut onbolt dis turned up, and the same provision is made at arm g, as SllOWllat z.

I claim as an improvement in extensionladders 1. In combination with theupper and lower sections of an extension-ladder and the pawl D by whichthe upper section is sustained at the desired height, the barf connectedat its lower end with bolt that pivots said pawl, and at its upper endis provided with the short arm g secured to the side of said uppersection, and so arranged as to support said bolt d, and to also arrestsaid pawl when it swings upward, substantially as specified.

2. In combination with the upper and lower sections of anextension-ladder and the pawl by which said upper section is sustainedat the desired height, the bar f arranged to receive bolt (1 that pivotssaid pawl, and having an arm secured to said upper section so as toarrest the upward swing of said pawl, and the lock 0 by which said upperand lower sections are secured together, extended inside of part B ofthe upper section to arrest the downward swing of said pawlsubstantially as specified.

CHARLES WV. 11. MOULTON.

YVitnesses:

T. W. PORTER, M. E. Bownrron.

